It is well known that pressurized containers of the aerosol bomb type comprise a can, most often cylindrical, that contains both the product to be dispensed and a pressurized propellant, as well as a valve to enable dispensing the product under the influence of the propellant and a device for actuation of the valve by the user.
The valve is generally disposed in the center of a cup that is crimped to the edge of the cylindrical can with a bead. It is actuated by a device that fits onto the pressurized container at the end having the valve. This device includes a skirt solidly joined to the cylindrical can in telescoping fashion or by being screwed to it; a regulating nozzle connected to the outlet tube of the valve, the outlet tube generally being fixed to the cup with the aid of a reinforcement; and a device for actuating the valve, hereinafter simply called a pushbutton, on which the user presses, and with which the valve can be made to operate and the product to be dispensed can be brought to the regulating nozzle.
Depending on how the product is to be dispensed, the pressurized container is made to function by keeping the valve at the top (a position hereinafter called top up) or at the bottom (a position hereinafter called top down). In the first case the valve is generally connected to a plunger tube located inside the container in such a way as to use the product contained until it is exhausted. If the container is used in an unsuitable position, the risk is that some of the propellant may escape by itself, without the product to be dispensed, or carrying only a small quantity of product to be dispensed with it.
In certain cases, which will be described in further detail below, it is necessary obligatorily to use the pressurized container initially in a first predetermined position, for example in order to allow a gas at overpressure or a protective gas different from the propellant to escape, with later use for distribution of the product being performed in the other position.
The user consequently runs the risk of using the container in the wrong position, resulting in a loss of the product or the propellant.
The attempt has thus been made to develop a system that locks the pushbutton and prevents the opening of the valve when the pressurized container is not in the proper position.